Refrigerating system



April 20, 1943. o. c. IRWIN REFRIGERATING SYSTEM Filed Sept. 12, 1932 2Sheets-Sheet l INVENTO ///el C. If

ATTORNEY April '20, 1943. o. C. IRWIN I REFRIGERATING SYSTEM Filed Sept.l2, 1932 2 Shets-Sheet 2 l |NvENTo- 0// er C -Irw/n fr ATTORN EYPatented Apr. 20, 1943'` REISSUED om 2- 194s mesne assignments,

Oliver I C. Irwin, New York, VN. Y., asslgnor, by to Standard Cap andSeal Corporation, Chicago, lll., a corporation of Vir- ApplicationSeptember 12, 1932, Serial No. 632,741

8 l Claims.

My invention relates to refrigeration systems and more particularly to asystem of mobile refrigeration. v

Insofar as this application is concerned, my invention will be describedin connection with refrigerated automobile trucks and trailers but itwill be apparent that certain phases of the invention will be applicableto refrigerated railway cars and other forms of mobile transportation.

Various attempts have been made to cool trucks by systems ofrefrigeration other than the old ice and salt method but none of thesesystems have been practical, either because of the complexity ofapparatus used, or the space requirements, or, as in all of the systems,including the ice and salt method, theV disadvantage of great additionalweight required to be carried by the truck.

It is one object of my invention toY provide a system of refrigerationfor mobile units wherein there are no moving parts on the truck andwherein the weight of apparatus and refrigerant Other and furtherobjects of my invention will be apparent from the following descriptiontaken in conjunction with the accompanying drawings wherein- Figure 1 isa diagrammatic illustration of soA fied arrangement and location ofapparatus; andl Fig. 6 is a partial plan view of a portion of theapparatus of Fig. 5.

I will first describe the reclamation or regenerating station which may=be a central depot.

At the outset it should be pointed out that the required as well as thespace occupied thereby are negligible factors on a truck or trailer.

My invention insofar as the'foregoing is concerned, consists 'of atleast two phases, namely, the particular arrangement of therefrigeration system and cycle, and specific improvements in theapparatus used.

The refrigeration system made use of is basically an absorption systemwith certain modifications. One of these modifications consists individing the absorption system into two parts, one of which is locatedon the mobile unit and the other of which is located at some point thatmight be referred to as a central depot or recharging station. There arecertain modifications that I have introduced into the system andapparatus by reason of this,Y division of functions of an absorptionrefrigeration cycle. y

It is another object of my invention to provide a system of refrigeratedmobile transportation wherein a loaded truck or trailer may be trans.-portedover long distances being periodically recharged with coolingagents at intermediate points along its journey, at which intermediatepoints would be located regenerating stations for the refrigerant andcooling agents.

It is still another object of my invention to provide a system ofcooling mobile refrigeration units in which the mobile unit is chargedwith precooled cooling agents.

It is a'further object of my invention to provide a systemlofrefrigeration using the absorption cycle wherein a compressor is'used toprecool the condensed refrigerant.

reclamation station that is hereinafter described is intended to handlethe charge from one truck or a fewtrucks at a time. A large centraldepot for handling the charges for a large number of trucks would havealarger assortment of apparatus to perform the special functionshereinafter described. One such system is outlined in my copendingapplication Ser. No. 632,740, iiled Sept. 12, 1932. .The refrigerantwill be assumed to be ammonia and the absorbing liquor water, althoughasis known in this art other combinations may be used.

A generator or still II having a heater I2 is adapted to receive astrong liquor (water in which the ammonia charge has been absorbed) fromthe truck in a manner to be hereinafter described. In the boiling thattakes place in the generator the ammonia is vaporized and passes fromthe still into a dehydrator I3, the purpose of which is to condense outof the ammonia vapor any Water vapor which may have escaped with theammonia vapor. For this purpose the dehydrator is water cooled, theinlet and outlet pipes of the water cooling system being indicated at I4and I5 respectively. Ammonia vapor then passes from the dehydrator I3through the pipes IB and I'I to the condenser I8. The condenser I8 maybe of the usual tubular type and is also water cooled, the inlet andoutlet pipes for the water circulatory system being indicatedrespectively at I9 and 20. Here the ammonia vapors are condensed and be-1 come liquid or anhydrous ammonia, which passes sofar as the normalrefrigeration cycle is concerned.

However, for reasons that will be explained hereinafter, I prefer topre-cool the refrigerant, that is to cool the saine before it isintroduced into the truck. For thispurpose and after the regeneration orreclamation of the refrigerant is completed, the valves 23 and 24 areclosed and the valves 25, 26 and 21 opened. Valve 24 shuts offcommunication between the condenser I8 and the dehydrator I3. Valve 25is located in the pipe 28 leading from the storage tank 22 and opensthis line while the valve 23 prevents communication of this line withthe dehydrator I3. Valves 26 and 21 open the branch lines 29 and 3|respectively to and from a compressor 32 that is driven by the motor 33.Ammonia. gas and vapor is drawn off the tank 22 by the compressorthrough the lines 28 and 29, compressed and discharged through the line3| back into the condenser I8 where the same is recondensed and returnedto the storage tank 22. This operation is continued progressivelyreducing the temperature of the ammonia to whatever degree is desired,even as low as 50 F. When the desired cooling is completed, valve 25 isclosed, the compressor is stopped, and the refrigerant is now in thecondition that I wish it to be when inserted into the truck. The storagetank 22 is completely enclosed with a layer of heat insulation 34.

The liquor remaining in the generator II after the refrigerant has beenboiled off is weak liquor, that is liquor from which the refrigerant hasbeen removed. I desire to also pre-cool that liquor. For this purposethe valve 4I will be Y opened and the weak liquor drawn from thegenerator II into the cooling tank 42. This tank is Water cooled, theinlet and outlet pipes of the water circulatory system being.respectively indicated at 43 and 44. The cooled weak liquor remains inthe tank 42 until ready to be placed upon the truck.

A simple absorption refrigeration cycle is normally the distilling offof the refrigerant vapor, the condensing thereof to produce the liquidrefrigerant, the passing of the liquid refrigerant through theevaporator, which is located in the unit to be cooled and by means ofwhich the heat in that unit is absorbed thereby vaporizing therefrigerant, the absorption of the spent refrigerant in the weak liquor,and the return of the now strong liquor to the generator where the cycleis again repeated. From the foregoing description it will be seen thatthere has only been set forth the reclamation and condensing of therefrigerant plus the pre-cooling of the refrigerant and the weak liquor.The remainder of the complete cycle is carried out on the mobile unit.

Referring to Figs. 2 and 4, there is shown one of a large number ofarrangements of apparatus upon the truck that is possible with myimproved system.

A truck chassis is indicated at 41 as supporting an insulated'truck body48, inside of which are a pair of sidewall cooling coils 49 and 5I and aroof cooling coil 52. Any one or all of these maybe used as needed inthe particular service to which a truck is to be put. Also on theindesiredpoint, or one tank 53 with associated valve 54 may be connectedto one set of the cooling coils and the other tank 53 with itsassociated valve 54 may be connected to the other cooling coil. Thetanks 53 are adapted to be filled with a pre-cooled refrigerant.

In the system shown in Figs. 2, 3 and 4, the cooling coils areinterconnected and terminate in a common return line 55 which extendsinto the interior of an absorber tank 56 located outside of theinsulated body 48. 'I'he absorber 56 is filled at the reclamationstation with weak liquor as will be hereinafter described. Therefrigerant is vaporized in the cooling coils that are inside the truckbody, the spent gases passing therefrom into the absorber 56, where theyare absorbed in the liquor contained therein.

The absorber tank 56 includes a pair of headers 51, 58, in between whichare disposed a plurality of finned pipes 59. The hot spent gases aredischarged near the bottom of the tank 56, pass out into the coolingcoils 59 and upwardly therein, being Vcooled in the passagetherethrough, and are discharged back into the tank 56 near the topthereof.

The air cooling of the absorber and the associated coils is accomplishedby locating this apparatus in a separate compartment 6I located in backof the drivers cab and ahead of the truck body 48. `This compartment isprovided at its bottom with an air scoop 62 open at its front asindicated at 63, and an air funnel 64 open at its rear as indicated at65 and terminating just above the top of the truck body 48. As the truckproceeds forwardly air isforced to enter the compartment 6I at thebottom, pass through the compartment over the tank 56 and the coolingtubes 59 and be passed from the compartment through the funnel 64 in adense large volume of air.

When the truck is ready to start its run, the

tank 53 is lled with pre-cooled refrigerant from y the tank 22, aflexible hose connection (not shown) being attached to the valveconnection 1I be permanently attached at 12 and be attached to the truckby any of the well known leak proof couplings. There may also beinterposed in this line a pump if necessary forthe transfer of therefrigerant from the tank 22 to the tanks 53.

At this point it is desirable to direct attention to the advantage ofthe use of the pre-cooled refrigerant. Succintly, that advantage may bestated to be that the refrigerant on the truck occupies a very much lessspace if pre-cooled and yet does the same amount of useful work on thetruck.

This is true because if it be assumed that ammonia that is notpre-cooled is at '75 F., and the unit to be cooled is to be maintainedat a temperature of 10 F., then the ammonia itself must first be cooledto 10 F. before beginning its useful work. This cooling of the ammoniais accomplished by boiling off enough of the ammonia itself so as totake up enough heat to cool the remainder to the 10 point. Thereafter,the remainder will continue cooling but will begin taking heat out ofthe body to be cooled. Accordingly, if it be assumed that it takes agiven tank of ammonia to maintain an object at 10 F. over apredetermined period of time and one quarter of that tank is required tofirst bring the ammonia down to that 10 tem.

perature before useful work is started of cooling the object, then it isat once apparent that if the ammonia is cooled to the point or belowbefore it is put into the truck, only that much need be put in the truckas is required to do the useful work. Or, in the assumed example, onequarter less space will be occupied by the refrigerant and one quarterless weight will have I to be carried by the truck ln order toaccomplish the desired result.

To complete the charging of the truck a flexible hose connection (notshown) is also made between the valved connection 13 on the tank 56 ofthe truck and the pump 14 'at the reclamation depot. When the truck isto be lled, the valves and 16 are opened and the pre-cooled weak liquorin the tank 42 is transferred from that tank to the tank 56. The valvedconnections 1| and 13 are closed and the hose connections are detached.'Ihe truck is now ready to begin its run which may be continued to thenext reclamation depot (if the run is a long one), or to the point ofdelivery where there may also be a reclamation depot.

At one or the other of these points the truck is emptied of coolingagents and the refrigerant is regenerated and pre-cooled ready torecharge the truck or to ll the next truck. This emptying of the truckis accomplished by re-establishing the hose connection between thevalved connections 1| and 12 withdrawing the unused refrigerant if anyfrom the cooling coils and the tanks in the body of the truck, thisrefrigerant being put in the storage tank 22. Also a detachable hoseconnection is made between the valved connections 13 for the absorbertanks 56 and the valved connection 11 for the pump 18. When thisconnection is made, the valves 11 and 19 are opened after the valve 15is closed. The liquor is then drawn out of the tank 56 and deposited inthe tank 42 or passed directly into the still by openingvthe valve 4|.When the tank 56 and associated coils are emptied the hose connection isdetached and the valve 16 is closed. After the` liquor is in thegenerator I, the valve 4| is closed. During this transfer the tank 42 isnot cooled.

l When the liquor is withdrawn from the tank 56,

it is no longer weak liquor but a strong liquor, that is it has a chargeof spent ammonia therein.

This completes a description of one cycle of operation of my improvedsystem and apparatus.

Figs. 5 and 6 illustrate a modified arrangement of apparatus. In thisshowing the chassis 8| supports an insulated truck body 82 having a pairof compartments 83, 84, supported by a smaller central compartment 85divided from the other two compartments by ventilated partitions 86.Located in the central compartment 85 are a pair of tanks 81 to each ofwhich is attached a cooling coil 88 extending parallel to the partitions86 on the respective sides of the compartment. Interposed between therespective tanks 81 and 88 is a valve 89. All of these parts ndcounterparts in the equipment on the interior of the truck of Figs. 2, 3and 4 and perform cor,

responding functions.

The coils 88 communicate with a common return line 9|, the branch 92 ofwhich extends through the bottom of the truck into the absorber tank 93located beneath the body of the truck and supported on the chassis bymeans of-the straps 94. The absorber tank 93 contains a supply of weakliquor which absorbs the ammonia gas spent in the cooling of the body ofthe truck as described above.

In order to dissipate the heat of the absorption of the spent gas intheweak liquor I provide a circulatory water system. A fluid pump 95 isintended to be driven either from thedrive shaft of the engine or by aseparate motor driven from the truck battery. The pump draws the liquidfrom the tank 93 and circulates the same through a radiator 96, thecooled liquor returning through the branch 91 to the tank 93. It will benoted that they cooling radiator 96 is placed in front of the truckahead of the normal engine radiator 98 of the truck so that the fan ofthe truck cooling system also draws air through the radiator 96 tofacilitate the cooling of the strong liquor. This cooling radiator couldbe disposed along the side of the truck body, if desired. The tanks 81are lled and emptied through the valve connection 99, and the Weakliquor or absorber tank 93 is drained and filled through the valvedconnection |00.

Otherwise, the equipment on the truck of Figs. I

5 and 6 is lled, emptied and functions exactly as described above inconnection with the truck shown in Figs. 2 to 4 inclusive.

At times it may be desirable to use the com-- .Ipressor 32 to exhaustthe absorber and cooling v tended to be covered by the appended claims.

I claim:

1. A refrigerated truck comprising a chassis having a drivers cab and aninsulated body carried by the chassis, an evaporator carried by thebody, cooling coils connected to the evaporator and disposedon theinterior of the body, an absorber o f an absorption refrigeration systemmounted outside of the body and ,connected to the cooling coils, meanswhereby the evaporator and absorber may be periodically re-supplied withfresh refrigerant and absorbent respectively, and a chimney surroundingsaid absorber to direct air thereover.

2. A refrigerated truck comprising a chassis having an insulated bodymounted thereupon, a plurality of evaporators carried by the body eachhaving an expansion valve and a cooling coil connected thereto, saidcoils being disposed on the interior of the body, an absorber of an ab-4sorption refrigeration system mounted outside of the body and connectedto the cooling coils and comprising a tank having extensive cooledsurfaces, and means whereby the evaporator and absorber may beperiodically re-supplied with fresh refrigerant and absorbentrespectively.

3. A refrigerated truck comprising a chassis having an insulated bodymounted thereupon, an evaporator carried by the body including coolingcoils disposed on the interior of the body, an absorber mounted beneaththe chassis and connected to the cooling coils and comprising a tankhaving extensive finned cooling surfaces, and means whereby theevaporator and absorber may be periodically re-supplied with freshrefrigerant and absorbent respectively.

4. A power moved refrigerated truck comprising a chassis having aninsulated body mounted thereupon, an evaporator carried by the bodyincluding cooling coils disposed on the interior of the body, anabsorber of an absorption refrigeration system mounted outside of thebody and connected to the cooling coils and comprising a coolingradiator mounted so as to receive a largey volume of air thereover dueto the forward motion of the truck. and means whereby the evaporator andabsorber may be periodically re-supplied with fresh refrigerant andabsorbent respectively.

5. A refrigerated truck comprising a chassis having an insulated bodymounted thereupon. an evaporator carried by the body including coolingcoils disposed on the interior of the body, a fan, an absorber mountedoutside of the body and connected to the cooling coils and comprising acooling radiator mounted at the forward end of the truck, so that air isdrawn over the radiator by the fan. y

6. A refrigerated truck comprising a chassis having an insulated bodymounted upon the chassis, an evaporator carried by the body.in-

of the body and connected to the cooling coils and comprising a tankhaving extensive cooling surfaces.

7. A refrigerated truck comprising a chassis having a drivers cab and aninsulated body carried by the chassis. an yevaporator carried by thebody comprising cooling coils disposed on the interior of the body, anabsorber of an absorption refrigeration system mounted outside of thebody and connected to the cooling coils and comprising a tank havingextensive cooling surfaces,

said absorber being mounted between the truck .ried by the chassis, anevaporator tank carried by the body, cooling coils connected to theevaporator tank and disposed on the interior of theV body, an absorberof an absorption refrigeration system mounted outside of the body andconnected to the cooling coils, means whereby the evaporator andabsorber may be periodically resuppliedv with fresh refrigerant andabsorbent respectively, means open to the normal direction of travel ofthe truck whereby air is caught and directed over said absorber, andadditional means for directing the air away from the absorber.

OLIVER C. IRWIN.

